Lemmara logoLemmaraWorked solution

4MA1/1F Jan 2021, Question 21: Solving Linear Equations

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 1F (Foundation) · Calculator · 5 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

Factorise the expression 15y⁴ + 20uy³ completely, then solve the equation 4 − 3x = (5 − 8x)/4 showing algebraic working.

Summarised in our own words. Use the official paper for the exact wording and any diagrams.

Part (a) · 2 marks

Factorise 15y⁴ + 20uy³ fully.

  1. 1HCF of 15 and 20 is 5; HCF of y⁴ and y³ is y³
  2. 2Take out 5y³: 15y⁴ ÷ 5y³ = 3y and 20uy³ ÷ 5y³ = 4u
  3. 35y³(3y + 4u)

Answer5y³(3y + 4u)

Part (b) · 3 marks

Solve 4 − 3x = (5 − 8x)/4, showing clear algebraic working.

  1. 1Multiply both sides by 4: 16 − 12x = 5 − 8x
  2. 2Collect terms: 16 − 5 = 12x − 8x, so 11 = 4x
  3. 3x = 11 ÷ 4 = 2.75

Answer2.75

Stuck on a step? Read the free lesson: Solving Linear Equations

Practise more solving linear equations questions

Real 4MA1 past-paper questions, marked on your working like the exam, with a worked solution for every part.

Practise free on Lemmara

More past-paper questions on solving linear equations

Also searched as: 4MA1 1F January 2021 · 4MA1/1F · 4ma1 jan21 1f · question 21.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.